Driven accessories in a hybrid vehicle may include, for example, an air conditioning compressor, a power steering pump, a power brake system, an alternator for supplying low-voltage electricity for lights and so forth, and/or a transmission oil pump. These accessories are generally powered by output from the engine. Some of the accessories in a hybrid vehicle may require power while the engine is off and the vehicle is being powered by an alternate power source such as an electric motor/generator.